Quoting Chris Roach
agree with J Cooper the main shot looks like an animated Megs and one down the line looks like animated prowl - all and all a good study of head designs!

Like I said below, just experimenting with a new style. Not sure if I'll run with it as I'm not sure I could do the animated style justice, but who knows, my inspiration tends to be a bit buckshot like at times.

Quoting LTE the Mechanier
Some of these feel very gundamy. Main pic reminds me of Starscream... Nice job! Now you just got to build bodies big enough to handle those heads and your ready to go!

The gundam thing was intentional. I'm thinking of entering Chris Roach's "dress the frame" contest, and it's one of his Gundam frames. I've never done anything gundamesque before and I needed a little practice to try and get the style right. Still not sure I'm there yet.